This was my Plainsman lab work area for mineral, frit, chemical, stain and metal oxide powders for developing glazes for customers and testing clay bodies and engobes. Not shown is the propeller mixer, perhaps the most important piece of equipment. And the plaster table for dewatering clay body slurries. Building up something like this, over time, is practical for any serious potter, many of these powders are inexpensive. Within minutes, I you can plan and enter a recipe into your Insight-live.com account, give it a code number, print it and weigh it out.

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You don’t have to invent a glaze from scratch to start making glazes your own. Begin with a documented recipe, make one controlled change and compare the results. This is G3933, made by adding iron oxide, rutile and tin oxide to a 75:25 blend of G2934 matte and G2926B glossy base glazes. I like it—but this mug gives me plenty of reasons to keep testing:
A small test kiln makes these questions practical to investigate. I can fire a few samples when I need to, compare each change with the original and use what I learn to decide the next step.

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I love making pottery, but I love the technical side more. I searched for all the test specimens in this 2020 load of cone 10 reduction ware first, then pushed it back in and forgot about it. For three months! I really anticipate the test results (I am developing and adjusting many of bodies and glazes at any given time). The data and pictures for them go into my account at insight-live.com, it enables me to compare the chemistry and physical properties of recipes and materials side-by-side. That teaches me which roads to abandon and which ones to pursue. My last kiln went back in for six weeks, so things are getting worse! If you are wondering, we use the C10RPL firing schedule.

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If you are at all serious about testing glazes and clay bodies, you need one of these. There are other methods, but nothing else comes close to this. It is the most valuable and frequently used tool in any ceramic bodies and glazes testing lab or classroom. This is the Lightnin brand, they are expensive but high quality. This is a 1/20 hp variable speed unit, it could be $4000 new! But you can get them used on ebay.com (the industrial mixers are most common, lab mixers are jealously guarded). This one uses a 7.9mm dia (5/16") shaft. We adapted a mount (to give it vertical adjustment) from small drill press.
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Ceramic Material
Ceramic materials are employed in the ceramic industry to make glazes, bodies, engobes and refractories. We study them at the mineral, chemical and physical levels. |
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Tony Hansen
Tony Hansen is the author of Digitalfire Insight, Digitalfire Reference Library and Insight-Live.com, he is a long-time potter, ceramic lab-technician and body and glaze developer. |
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Slurry Up
The process of slurrying a clay body powder and dewatering it on a plastic slab or table. |
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